Rhythm: a/v rhythms are irregular, with shortest PP or RR interval varying at least 0.12sec from the longest PP or RR interval

P waves: one P wave before ea QRS complex, consistent configuration

PR interval: normal, constant

QRS duration: normal, constant

What are dysrhythmias?

Any disorder of the heartbeat

Result from:

A disturbance in the relationship btwn electrical conductivity and the mechanical response of the myocardium

A disturbance in impulse formation (either from an abnormal rate or from an ectopic focus)

A disturbance in impulse conduction (delays and blocks)

The combination of several mechanisms

What are tachydysrhythmias?

HR > 100bpm

Major concern in adult pt with coronary artery disease (CAD)

Coronary artery blood flow occurs mostly during diastole when the aortic valve is closed and is determined by diastolic time and BP in the root of the aorta

They shorten the time and therefore the coronary perfusion time (the amount of time available for blood to flow through the coronary arteries to the myocardium)

Initially increases CO and BP; however, a continued rise in HR decreases the ventricular filling time because of a shortened diiastole , decreasing the stroke volume. Consequently, CO and BP will begin to decrease, reducing aortic pressure and therefore coronary perfusion pressure